The bottle of Diesel Kleen +Cetane Boost I purchased does not have the “endorsed by Cummins” on it? It is the same product as in bottles that do have the endorsement on the label?

Yes, the product is the same no matter the label. Power Service Diesel Kleen +Cetane Boost is endorsed by Cummins. No changes have been made to the formula, so every bottle carries this endorsement regardless of labeling – which is being updated to reflect Cummins’ confidence in the product